High-pressure relief belleville valve

ABSTRACT

A high-pressure relief valve is constructed of a Belleville-type spring washer preloaded in a housing to serve as a resilient barrier to fluid flow between inlet and outlet openings in the housing. Means are provided for reducing the pressure effect of the fluid on the washer to thereby increase the pressure required to actuate the valve. This is accomplished by reducing the area of effective pressure on the face of the washer.

llnited States Patent Allen 1 Mar. 7, 1972 [54] HIGH-PRESSURE RELIEFBELLEVILLE 2,585,863 2/1952 Smith ..137/525 VALVE 2,676,614 4/1954Strauss et al ..137/516 [72] Inventor: Thomas E. Allen, East Peoria,111. FOREIGN PATENTS OR APPLICATIONS [73] Assignee: Caterpillar TractorCo., Peoria, 111. 1,244,909 9/1960 France ..137/525 (22] Wed: 1970Primary Examiner-Robert G. Nilson [21 1 Appl 30 79 Attorney-Fryer,Tjensvold, Feix, Phillips & Lempio [57] ABSTRACT [52] US. CL. 137/525 Iv 51 Int. Cl ..Fl6k 15/14 A s -P rellef valve IS constructed ofBfllevllle-lype [58] Field of Search "mtg/516 525 spring washerpreloaded in a housing to serve as a resilient barrier to fluid flowbetween inlet and outlet openings in the housin Means are rovided forreducin the ressure eff ct R r (:1 ed 8 P g P e [56] 2 new t of thefluid on the washer to thereby increase the pressure UNH'ED S S P TENTSrequired to actuate the valve. This is accomplished by reducing the areaof effective pressure on the face of the washer. 3,179,122 4/1965Wasdell ..137/525 X 3,363,729 1/1968 Rumsey ..137/525 X 7 Claims, 5Drawing Figures PATENTEDHAR 1 I972 INVENTOR THOMAS E. ALLEh r7 W i @4 4lb rf w ATTORNEYS HIGH-PRESSURE RELIEF BELLEVILLE VALVE BACKGROUND OFTHE INVENTION The present invention relates to high pressure reliefvalves and pertains more particularly to Belleville-type relief valves.

High-pressure fluid-handling systems generally employ pressure reliefvalves to limit pressures in certain portions of the system.Conventionally such systems employ spool valves or poppet valves.

Spool valves employ a spring-biased spool which moves in response topredetermined pressure to dump fluid generally back to the sump. Spoolvalves have the disadvantage of being expensive and subject to jammingor sticking because of the extremely close tolerances required. Also,because of their size, they consume valuable space and tend to havelarge inertia which causes slow response, overshooting, and hunting."

Poppet valves, on the other hand, tend to have a restricted flow volume.Spring washer type relief valves have been restricted to operatingpressures of less than l,000 pounds per square inch due to high valvemember stresses and high preload forces.

SUMMARY OF THE INVENTION The primary object of the present invention isto provide a low-cost reliable relief valve that is suitable forhigh-pressure applications.

Another object of the present invention is to provide a compact reliefvalve that is reliable in operation and is capable of high flow rates.

In accordance with the present invention, a housing is provided with apreloaded Belleville washer serving as a resilient barrier between ahigh-pressure inlet opening and an outlet opening in .the housing. Thewasher is responsive to a predetermined fluid pressure to permit saidfluid to flow past the outer periphery thereof to the outlet opening.Means are provided to limit the effective fluid pressure on the washer.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of apreferred embodiment of the present invention;

FIG. 2 is an isometric view in section of the outlet housing and controlelements of the embodiment of FIG. 1;

FIG. 3 is a fragmentary view showing details of FIG. 1;

FIG. 4 is a sectional view of an alternate embodiment of the presentinvention;

FIG. 5 is a fragmentary view showing details of FIG. 4.

DETAILED DESCRIPTION OF THE DRAWINGS Referring now to the drawings andmore particularly to FIG. 1, there is illustrated a pressure reliefvalve incorporatingthe preferred embodiment of the present invention.The pressure relief valve comprises housing having an annular chamber 11formed therein and enclosed by means of a cover 12 held in place such asby means of capscrews 13. The cover 12 is preferably sealed to thehousing 10 by means of a seal 14. An inlet opening 15 communicates bymeans of a conduit 16 with a source of pressurized fluid (not shown) andan outlet opening 17 communicates with a sump or other circuit (notshown). A Belleville-type spring washer 18 is positioned within thehousing to function as a valve element and to form a resilient barrierbetween the inlet opening 15 and the outlet opening 17. This serves as abarrier to pressurized fluid to prevent the passage of fluid fromchamber 19 in cover 12 at the concave side of the washer from escapingpast the outer diameter thereof into chamber 11 where it then passes outoutlet 17. The washer 18 is supported by support means 20 and preloadedbetween shoulders 21 thereon acting as a fulcrum and outer rim 22 ofcover 12 forming a valve seat. The preload of spring 18 is overcome bymeans of force acting on its face or concave side 18a which is normallya function of the pressure times the area. However, in order toeffectively increase the pressure responsiveness, means are provided toreduce the pressure effect on said concave side of the washer.

This pressure effect reducing means in the present embodiment comprisesmeans for transferring or communicating the pressurized fluid from theinlet opening and placing it in contact with a portion of the convexside 18b of the spring-washer 18. This pressure effect reducing meanscomprises a plurality of passageways 23 for communicating fluid fromchamber 19 into an annular chamber 24 formed in housing 10. An annularring or sleeve 25 is slidably mounted in annular chamber 24 and carriesa ring seal 26 which is in tight engagement with the convex side 18b ofthe washer 18. This arrangement effectively permits pressurized fluidtoact on the convex side 18b of the spring washer 18 to offset a portionof the pressure acting on the concave side thereof. Thus the effectivepressure, that is, the pressure which is effective to actuate the valvemember 18, is the pressure that acts on the area of face 18a which is inexcess of the area or fluid contact area on face 18b. This effect can bemore easily visualized in FIG. 3 where it is seen that the outerdiameter of the fluid contact of face 18a is somewhat greater than theouter diameter of the fluid contact of 18b. Thus, instead of attemptingto increase the stiffness of the spring washer, the force applied to thewasher for a given fluid pressure is reduced. This enables one to keepthe stiffness and thickness of the washer to a minimum so that it can bemore easily controlled.

One could alter the construction of FIG. 1 by fixing sleeve 25 to thehousing 10 or providing a similar annular abutment, integral with thehousing, such that the valve member pivots about the abutment ratherthan support member shoulder 21. Although this construction offersmanufacturing advantages, flow rate capacity is somewhat reduced.

Referringnow to FIGS. 4,and 5, there is illustrated an alternateembodiment of the'present invention. In this embodiment, the pressurerelief valve assembly comprises a housing 30 having an annular chamber31 formed therein and enclosed by a cover 32 held in place such as bycapscrews 33. A sea] 34 is provided for sealing the chamber. The cover32 has an annular chamber 35 formed therein and ,an inlet opening 36communicating therewith such as by means of a conduit 37 from a sourceof pressurized fluid (not shown). An outlet opening 38 formed in housing30 provides communication between annular chamber 31 and a sump or otherfluid circuit (not shown). A Belleville-type spring washer 39 is carriedon support means 40 and preloaded between shoulder or fulcrum 41 and anannular valve seat comprising rim or surface 42of cover 32. The springwasher 39 provides a resilient barrier between the inlet opening 36 andchamber 35 and the chamber 31 and outlet opening 38, for fluid containedin chamber 35 under a predetermined pressure.

Means are provided for reducing the effective pressure on the concaveside 3911 of the spring 39. This pressure effect reducing meanscomprises an annular sleeve comprising seal 43 having a backing ring 44and mounted on cylindrical surface 45. The seal member 43 slides alongface 45 and engages face 39a on the concave side of spring member 39.This in effect reduces the effective force on spring member 39 byreducing the contact area of pressurized fluid along face 39a. Thus, ascan be seen more readily in FIG. 5, the pressurized fluid acting on face38a of washer member 39 is confined to an area within an annular chamber35 between seal member 43 and the annular shoulder 42. Thus, as can beseen, because of the small area contact of pressurized fluid, theresponsiveness of spring or washer member 39 is altered such that a veryhigh fluid pressure is needed to actuate the valve member.

Thus from the above disclosure it can be seen that I have disclosed ahigh pressure relief valve comprising a housing forming a chamber with aBelleville-type washer contained therein, forming a resilient barrierbetween inlet opening and an outlet opening for pressurized fluid belowa predetermined level, with means to reduce the pressure effect on theconcave side of the washer.

What is claimed is:

1. A high pressure relief valve, said valve comprising:

housing means forming a chamber;

an inlet opening formed in said housing for communicating said chamberwith a source of pressurized fluid;

an outlet opening formed in said housing and communicating with saidchamber;

a Belleville-type spring washer having convex and concave faces forminga barrier in said housing between said openings; v 5

said washer being preloaded and thereby responsive to a predeterminedfluid pressure on the concave side thereof to spring back and permit aflow of fluid around the outer diameter thereof;

pressure effect reducing means comprising a sleeve member slidablymounted in said housing in annular engagement with said washer; and,

means for directing said fluid pressure into contact with a portion ofthe convex side of said washer to thereby offset the efi'ect of aportion of said fluid in engagement with the concave side thereof.

2. A high pressure relief valve, said valve comprising:

a housing having a chamber formed therein;

inlet and outlet openings 7 communicating with said chamber;

an annular valve seat disposed in said chamber;

support means to form a fulcrum disposed opposite said valve seat insaid housing;

an annular resilient washer having inner and outer diameters andoppositely directed faces mounted between said support means and valveseat;

said washer being supported at one of said diameters by said supportmeans and engaging said valve seat adjacent the other of said diametersto function as a pressure responsive valve element to control flow offluid between said inlet and outlet openings;

said washer being responsive to fluid pressure acting on one of saidfaces to pivot said washer away from said valve seat to permit fluid toflow thereby; and,

an annular sleeve slidably mounted in said housing and sealinglyengaging said washer between said valve seat and said fulcrum to reducethe area of effective pressure for actuating said valve.

3. The invention of claim 2 wherein said washer is a Belleville-typehaving convex and concave faces.

4. The invention of claim 3 wherein said sleeve engages said convex faceto direct pressurized fluid to a portion thereof.

5. The invention of claim 3 wherein said sleeve engagessaid concave faceto reduce the area of fluid contact therewith.

6. The invention of claim 3 wherein said washer is supported at theinner diameter and said outer diameter engages said annular seat.

7. The invention of claim 6 wherein said sleeve engages the convex faceof said washer; and,

means to direct pressurized fluid to a portion of said convex face.

1. A high pressure relief valve, said valve comprising: housing meansforming a chamber; an inlet opening formed in said housing forcommunicating said chamber with a source of pressurized fluid; an outletopening formed in said housing and communicating with said chamber; aBelleville-type spring washer having convex and concave faces forming abarrier in said housing between said openings; said washer beingpreloaded and thereby responsive to a predetermined fluid pressure onthe concave side thereof to spring back and permit a flow of fluidaround the outer diameter thereof; pressure effect reducing meanscomprising a sleeve member slidably mounted in said housing in annularengagement with said washer; and, means for directing said fluidpressure into contact with a portion of the convex side of said washerto thereby offset the effect of a portion of said fluid in engagementwith the concave side thereof.
 2. A high pressure relief valve, saidvalve comprising: a housing having a chamber formed therein; inlet andoutlet openings communicating with said chamber; an annular valve seatdisposed in said chamber; support means to form a fulcrum disposedopposite said valve seat in said housing; an annular resilient washerhaving inner and outer diameters and oppositely directed faces mountedbetween said support means and valve seat; said washer being supportedat one of said diameters by said support means and engaging said valveseat adjacent the other of said diameters to function as a pressureresponsive valve element to control flow of fluid between said inlet andoutlet openings; said washer being responsive to fluid pressure actingon one of said faces to pivot said washer away from said valve seat topermit fluid to flow thereby; and, an annular sleeve slidably mounted insaid housing and sealingly engaging said washer between said valve seatand said fulcrum to reduce the area of effective pressure for actuatingsaid valve.
 3. The invention of claim 2 wherein said washer is aBelleville-type having convex and concave faces.
 4. The invention ofclaim 3 wherein said sleeve engages said convex face to directpressurized fluid to a portion thereof.
 5. The invention of claim 3wherein said sleeve engages said concave face to reduce the area offluid contact therewith.
 6. The invention of claim 3 wherein said washeris supported at the inner diameter and said outer diameter engages saidannular seat.
 7. The invention of claim 6 wherein said sleeve engagesthe convex face of said washer; and, means to direct pressurized fluidto a portion of said convex face.